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Merge pull request #5445 from CodingFabian/fixImageCachingInParser

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Fixes caching of inline images during parsing.
This commit is contained in:
Yury Delendik 2014-12-15 10:51:23 -06:00
commit f5df30f967
2 changed files with 34 additions and 37 deletions
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31
src/core/evaluator.js
View File

@ -171,7 +171,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
buildPaintImageXObject: buildPaintImageXObject:
function PartialEvaluator_buildPaintImageXObject(resources, image, function PartialEvaluator_buildPaintImageXObject(resources, image,
inline, operatorList, inline, operatorList,
cacheKey, cache) { cacheKey, imageCache) {
var self = this; var self = this;
var dict = image.dict; var dict = image.dict;
var w = dict.get('Width', 'W'); var w = dict.get('Width', 'W');
@ -209,9 +209,10 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
args = [imgData]; args = [imgData];
operatorList.addOp(OPS.paintImageMaskXObject, args); operatorList.addOp(OPS.paintImageMaskXObject, args);
if (cacheKey) { if (cacheKey) {
cache.key = cacheKey; imageCache[cacheKey] = {
cache.fn = OPS.paintImageMaskXObject; fn: OPS.paintImageMaskXObject,
cache.args = args; args: args
};
} }
return; return;
} }
@ -260,9 +261,10 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
operatorList.addOp(OPS.paintImageXObject, args); operatorList.addOp(OPS.paintImageXObject, args);
if (cacheKey) { if (cacheKey) {
cache.key = cacheKey; imageCache[cacheKey] = {
cache.fn = OPS.paintImageXObject; fn: OPS.paintImageXObject,
cache.args = args; args: args
};
} }
}, },
@ -656,8 +658,8 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
} }
// eagerly compile XForm objects // eagerly compile XForm objects
var name = args[0].name; var name = args[0].name;
if (imageCache.key === name) { if (imageCache[name] !== undefined) {
operatorList.addOp(imageCache.fn, imageCache.args); operatorList.addOp(imageCache[name].fn, imageCache[name].args);
args = null; args = null;
continue; continue;
} }
@ -706,10 +708,13 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
}, reject); }, reject);
case OPS.endInlineImage: case OPS.endInlineImage:
var cacheKey = args[0].cacheKey; var cacheKey = args[0].cacheKey;
if (cacheKey && imageCache.key === cacheKey) { if (cacheKey) {
operatorList.addOp(imageCache.fn, imageCache.args); var cacheEntry = imageCache[cacheKey];
args = null; if (cacheEntry !== undefined) {
continue; operatorList.addOp(cacheEntry.fn, cacheEntry.args);
args = null;
continue;
}
} }
self.buildPaintImageXObject(resources, args[0], true, self.buildPaintImageXObject(resources, args[0], true,
operatorList, cacheKey, imageCache); operatorList, cacheKey, imageCache);

40
src/core/parser.js
View File

@ -28,16 +28,14 @@ function isEOF(v) {
return (v === EOF); return (v === EOF);
} }
var MAX_LENGTH_TO_CACHE = 1000;
var Parser = (function ParserClosure() { var Parser = (function ParserClosure() {
function Parser(lexer, allowStreams, xref) { function Parser(lexer, allowStreams, xref) {
this.lexer = lexer; this.lexer = lexer;
this.allowStreams = allowStreams; this.allowStreams = allowStreams;
this.xref = xref; this.xref = xref;
this.imageCache = { this.imageCache = {};
length: 0,
adler32: 0,
stream: null
};
this.refill(); this.refill();
} }
@ -185,34 +183,29 @@ var Parser = (function ParserClosure() {
var length = (stream.pos - 4) - startPos; var length = (stream.pos - 4) - startPos;
var imageStream = stream.makeSubStream(startPos, length, dict); var imageStream = stream.makeSubStream(startPos, length, dict);
// trying to cache repeat images, first we are trying to "warm up" caching // cache all images below the MAX_LENGTH_TO_CACHE threshold by their
// using length, then comparing adler32 // adler32 checksum.
var MAX_LENGTH_TO_CACHE = 1000; var adler32;
var cacheImage = false, adler32; if (length < MAX_LENGTH_TO_CACHE) {
if (length < MAX_LENGTH_TO_CACHE && this.imageCache.length === length) {
var imageBytes = imageStream.getBytes(); var imageBytes = imageStream.getBytes();
imageStream.reset(); imageStream.reset();
var a = 1; var a = 1;
var b = 0; var b = 0;
for (i = 0, ii = imageBytes.length; i < ii; ++i) { for (i = 0, ii = imageBytes.length; i < ii; ++i) {
a = (a + (imageBytes[i] & 0xff)) % 65521; // no modulo required in the loop if imageBytes.length < 5552
b = (b + a) % 65521; a += imageBytes[i] & 0xff;
b += a;
} }
adler32 = (b << 16) | a; adler32 = ((b % 65521) << 16) | (a % 65521);
if (this.imageCache.stream && this.imageCache.adler32 === adler32) { if (this.imageCache.adler32 === adler32) {
this.buf2 = Cmd.get('EI'); this.buf2 = Cmd.get('EI');
this.shift(); this.shift();
this.imageCache.stream.reset(); this.imageCache[adler32].reset();
return this.imageCache.stream; return this.imageCache[adler32];
} }
cacheImage = true;
}
if (!cacheImage && !this.imageCache.stream) {
this.imageCache.length = length;
this.imageCache.stream = null;
} }
if (cipherTransform) { if (cipherTransform) {
@ -221,10 +214,9 @@ var Parser = (function ParserClosure() {
imageStream = this.filter(imageStream, dict, length); imageStream = this.filter(imageStream, dict, length);
imageStream.dict = dict; imageStream.dict = dict;
if (cacheImage) { if (adler32 !== undefined) {
imageStream.cacheKey = 'inline_' + length + '_' + adler32; imageStream.cacheKey = 'inline_' + length + '_' + adler32;
this.imageCache.adler32 = adler32; this.imageCache[adler32] = imageStream;
this.imageCache.stream = imageStream;
} }
this.buf2 = Cmd.get('EI'); this.buf2 = Cmd.get('EI');